By now it's very clear, it can't be medium of exchange.
"A speculator is a person who trades derivatives, commodities, bonds, equities or currencies with a higher than average risk in return for a higher-than-average profit potential" https://www.investopedia.com/terms/s/speculator.asp
You can say what you want about the philosophy of that - the lightning network will add yet another group of people who collectively have an outsized control over the network. But if the scaling issues get addressed I don't see any reason why it couldn't work as a currency. And it looks like they are being (slowly) addressed.
Blockstream struck down a modest increase to 2MB in November. They have devs who want to reduce the blocksize. I'm not sure where you're finding hope in LN.
Bitcoin Cash forked off to get back to scaling, and it's doing great. Check out how well the mempool stress test went this past week.
Current prevailing theory in BCH land is the block size is an unnecessary hinderance, and will likely be gone in the next 18 months.
Exciting times!
What are you smoking? Even 1GB blocks would be 144GB per day of blockchain growth. You can't expect people to tolerate that kind of disk usage, let alone bandwidth.
By the time they're necessary, it'll be a lot less demanding, relatively speaking....